The Interagency DNAPL Consortium (IDC) representing the U.S. EPA, NASA, DoE, DoD, and U.S. Air Force conceived a demonstration to test three technologies for DNAPL remediation. The Technical Advisory Group (TAG), consisting of nationally known experts in the field of DNAPL remediation, conducted the technology evaluation, MSE Technology Applications managed the demonstration. Out of the final technologies (chemical oxidation, steam injection, surfactant flushing, electrical resistance heating) evaluated for testing, electrical resistance heating received the highest ranking by the TAG based on its robustness, expected time required for remediation, cost of implementing the technology and regulatory acceptance.

The ERH system was designed to fit inside of a 50-foot wide and 75 foot long rectangular cell adjacent and partially underneath the Engineering Services Building at Launch Complex 34 (ESB) in Cape Canaveral, Florida. The system consisted of a network of 13 electrodes, 3 of which were installed at an angle underneath the ESB, The electrodes were electrically conductive at two intervals between 21 - 30 feet bgs and 33-46 feet bgs. The two intervals were designed to heat the DNAPL in the middle fine grain unit and the lower clay unit. Vapor extraction wells were screened at 5 feet bgs. There was also a network of horizontal vapor extraction wells installed at the surface underneath a plenum. There were four temperature-monitoring points with thermocouples located at 5-foot intervals.

The desired remediation goal for the demonstration was a 90% reduction of the TCE DNAPL as measured in soil. The electrical resistance heating demonstration at Launch Complex 34 achieved a 90% reduction of the TCE mass and a 97% reduction of the TCE DNAPL mass.

Related products

Related articles

ABSTRACT
High density sampling program was key to remediation of soil and groundwater impacted by TCE DNAPL at a former industrial site underlain by river deposits and sedimentary bedrock.
CHALLENGES
Impacted alluvium consisted of poorly sorted, fine to coarse grained sand. The source area was underlain by an aquitard of silt and clayey silt where dense non-aqueous phase liquid (DNAPL) pooled at the interface. Impacts did not extend into the underlying claystone bedrock. Solute transport was dictated by...